Epinephrine, norepinephrine and dopamine concentrations in amphibian brain.

The whole brain concentrations of epinephrine, norepinephrine and dopamine in North American amphibians, orders Caudata and Salientia, are reported. Epinephrine is the major catecholamine in the Salientia while norepinephrine and epinephrine concentrations are roughly equivalent in suborders of Caudata. Relative regional concentrations are similar to other classes (mammals, reptiles and birds) although the absolute concentration of epinephrine is considerably higher in amphibians than in most other species.